Uncorrected Proof 1 © IWA Publishing 2020 Water Supply | in press | 2020 Geo-spatial distribution of fluoride in drinking water resources in Eastern of Iran Nourahmad Nourafrouz, Ali Naghizadeh, Borhan Mansouri, Hamed Biglari and Elham Derakhshani ABSTRACT The purpose of this study was to determine the fluoride concentrations in drinking water of the Khaf Nourahmad Nourafrouz Department of environmental health engineering, County in Eastern Iran. Moreover, health risk assessment of three age groups (children, teens and Student Research Committee, Faculty of Health, Birjand University of Medical Sciences, adults), sensitivity analysis and uncertainties in the risk estimates were carried out using Monte Carlo Birjand, simulation. For this reason, drinking water in 33 villages and 5 cities of the Khaf County were Iran collected during March to September 2018. Fluoride contents in drinking water samples were Ali Naghizadeh (corresponding author) Elham Derakhshani assayed by using a HACH-DR6000 spectrophotometer. Fluoride content in drinking water from urban Medical Toxicology and Drug Abuse Research À1 À1 Center (MTDRC) (BUMS), area and rural area ranged from 0.50 to 0.91 mg L and 0.24 to 2.31 mg L . Among population of 33 Birjand University of Medical Sciences, villages, about 17 villages corresponding to 51%, receive fluoride concentrations less than 0.5 mg LÀ1 Birjand, Iran (minimum allowable concentration recommended by WHO), while the population of 4 villages E-mail: [email protected] À1 corresponding to 12%, receive fluoride concentrations higher than 1.5 mg L (the maximum Borhan Mansouri fl Substance Abuse Prevention Research Center, allowable concentration of uoride in drinking water recommended by the WHO). Moreover, our Health Institute, findings showed that the drinking water ingestion rate, fluoride concentration in water, and the Kermanshah University of Medical Sciences, Kermanshah, fraction of skin in contact with water were the most important variable in calculating the Hazard Iran quotient (HQ). Hamed Biglari Department of Environmental Health Engineering, Key words | drinking water, fluoride, fluorosis, health risk School of Public Health, Social Development & Health Promotion Research Center, Gonabad University of Medical Sciences, Gonabad, Iran INTRODUCTION Nowadays, a readily available access to safe drinking water manganese, and fluoride which exist in drinking water resources is an important aspect of public health in many are essential for metabolic activates as well as human countries around the world including Iran (Garg & Malik health (Nerbrand et al. ; Li et al. ; Kazi et al. ; Fallahzadeh et al. ). Iran is a vast country, and a, b). However, increasing the concentration of has diverse climatic conditions in comparison to other trace elements in relation to the required level in the countries. Khorasan Razavi is located in the northeast of body can lead to health problems. Contamination of drink- Iran. In the southern part of this province because of its ing water to fluoride and its potential health implications close proximity to the desert, the dry climate is dominant remain a major public health issue in many countries, (Keshavarzi et al. ; Madani ; Soltani et al. ). especially in Iran (Yousefi et al. ). Therefore continu- Providing safe and quality drinking water will have a sig- ous monitoring and control of drinking water quality is nificant impact on sustaining life and social health. very important (WHO ). Generally; Potable water contains both essential and non- Fluoride (F) is one of the mineral elements exist in the essential elements. A lot of elements such as calcium, earth’s crust. This F ion is highly reactive due to presence of doi: 10.2166/ws.2020.105 Downloaded from https://iwaponline.com/ws/article-pdf/doi/10.2166/ws.2020.105/693536/ws2020105.pdf by guest on 01 June 2020 Uncorrected Proof 2 N. Nourafrouz et al. | Fluoride in drinking water resources in Eastern Iran Water Supply | in press | 2020 a free electron in its upper electron layer, and is mostly pre- reported that more than 30 million people in China suffer sent in compounds such as cryolite, apatite, and cryolite in from fluorosis and about 100 million people are exposed nature (Kır et al. ). Contamination of surface and ground- to it (Chen et al. ). In another study conducted by water by fluoride can be traced to natural resources Huang et al. () who reported that the concentration of (availability and solubility of fluoride minerals and fluoride- fluoride in groundwater in California is more than À bearing rocks) and anthropogenic resources (hydrofluoric 1.5 mg L 1 (Huang et al. ). production, fertilization, electroplating of metals, the elec- Moreover, the variations of fluoride concentration in tronics manufacturing industry) (Tor ; Xu et al. ). drinking water are one of the main problems in drinking The World Health Organization (WHO) has recommended water quality in Iran. In some cities of Iran, the amount of À the minimum and maximum allowable concentration of flu- fluoride in drinking water is higher than 1.5 mg L 1, which À oride in drinking water as 0.5 and 1.5 mg L 1 respectively. can lead to fluorosis (Asgari et al. ). For example Defluoridation processes recommended for water supplies Qasemi et al. () reported that 55% of the rural areas in which their fluoride concentration is higher than the stan- Gonabad and 4.7% of the rural areas in Bajestan had dards (Kazi et al. a, b). fluoride levels below the minimum recommended value of Also, according to the United States Public Health Ser- WHO (Qasemi et al. ). In another study, Ghaderpoori vice (USPHS) the maximum allowable concentration of et al. () illustrated that the fluoride levels from all fluoride in water depends on climate conditions because sampling stations in water distribution network of Mashhad À air temperature affects the amount of water consumed in Eastern of Iran were below of 0.5 mg L 1 (Ghaderpoori and consequently the exposure to the amount of fluoride et al. ). Therefore, the aim of this study was to determine (USPHS ; WHO ; Miretzky & Cirelli ). The the fluoride concentration of drinking water in 33 villages optimal water fluoride concentration depends on several and 5 cities of the Khaf County, which located in southern parameters such as methods of food processing and cook- part of Khorasan Razavi province, from March to Septem- ing, amount of food and water intake, dietary habits of ber 2018. Moreover, we assessed the potential health risks the community, local climatic conditions, and physio- from fluoride ingestion through drinking water for infants, chemical parameters of water (Grimaldo et al. ; children, teenagers and adults. The results of this study Kaseva ; Maheshwari ). Although drinking water could be useful for future planning of water resources as is the main source of human exposure to fluoride, but well as public knowledge about health problems related food, dental products, and pesticides are another important with fluoride high concentrations. sources for dealing with fluoride (Garg & Malik ; Council ). Fluoride fluctuations can be associated with health pro- MATERIALS AND METHODS blem of consumers, so that low fluoride concentrations causes tooth decay, and high concentration of this element The present study was descriptive-analytical and was per- in water increase the risk of dental and bone fluorosis. formed experimentally on drinking water resources of According to previous studies, nearly 80% of prevalence Khaf County in Khorasan Razavi Province of Iran for deter- and incidence of a diseases in all over the world are related mination of the fluoride ion concentration. The Khaf County to low water quality. Also contamination of drinking contains five cities including Khaf, Nashtifan, Qasemabad, water with fluoride accounts for 65% of endemic fluorosis Salami, and Sangan. The climate of this region is hot and (Chronicle ). Moreover, long term exposure to high dry, i.e., hot summers and cool winters. The mean annual fluoride concentrations may lead to various diseases such temperature and rainfall in Khaf County are 18 C and as dental and skeletal fluorosis, low hemoglobin levels, 120 mm respectively and the annual average of rainfall is skin rashes, glands damage, gastrointestinal problems, infer- about 255.7 mm. At 2016 census the county’s population tility, abortions, neurotoxicological effects, and Alzheimer was 140,000 in 26,542 families. In the present study, all (Sehn ; Choi et al. ; Choi et al. ). In a research drinking water resources (38 wells and springs: 5 cities Downloaded from https://iwaponline.com/ws/article-pdf/doi/10.2166/ws.2020.105/693536/ws2020105.pdf by guest on 01 June 2020 Uncorrected Proof 3 N. Nourafrouz et al. | Fluoride in drinking water resources in Eastern Iran Water Supply | in press | 2020 and 33 villages) were sampled in spring and summer of 2018 ; Fakhri et al. ): and their fluoride concentration was determined. The sampling locations as well as the map of Khaf County are Cw × IRw × EF × ED EDI ¼ (1) shown in Figure 1. ing BW × AT Prior to sampling and to access the drinking water À Cw × SA × Kp × F × ETs × EF × ED × 10 3 resources necessary coordination with the Water and EDI ¼ derm BW × AT Wastewater Administration was carried out and required (2) permissions obtained. One-liter polyethylene containers were used to sampling of water from the studied areas. The containers were rinsed with acid and distilled water, In this regard, EDIing estimates daily intake of fluoride and thoroughly cleaned before sampling. The date, time, consumed per day by drinking water and EDIderm estimates and location of sampling were recorded on all of sampling the amount of fluoride received by skin absorption based À1 À1 container. Then, samples were transferred to the laboratory on mg kg day .Cw is the concentration of fluoride in fl À1 by storing the cold chain (in 4 C). Finally, uoride concen- drinking water in mg L ,IRw is the drinking water inges- trations in water samples were determined within 24 h after tion rate based on L/day, EF is the exposure frequency collection at laboratory by using a HACH-DR6000 spectro- based on day/year, ED is the exposure duration in terms photometer machine with SPADNS reagent.